Multi-color original for an electrophotographic printing system

ABSTRACT

A sheet in which the structure thereof is such as to facilitate the formation of a color original for use in a multi-color electrophotographic printing machine arranged to produce copies thereof. The sheet has an opaque portion and a transparent portion corresponding to indicia thereon. Colored material is disposed on one surface of the sheet such that to an observer the other surface is opaque with colored indicia being visible through the transparent portion thereof.

[ Sept. 30, 1975 [54] MULTLCOLOR ORIGINAL FOR AN FOREIGN PATENTS OR APPLICATIONS 1,077,831 8/1967 United Kingdom..................... 355/4 ELECTROPHOTOGRAPHIC PRINTING SYSTEM Inventor:

[75] James M. McVeigh, Rochester, NY.

Primary Examiner-Robert P. Greiner Attorney, Agent, or FirmH, Fleischer; J. J. Ralabate; C A. Green [73] Assignee: Xerox Corporation, Stamford,

Conn.

[57] ABSTRACT A sheet in which the structure thereof is such as to fa- [22] Filed: Sept. 26, 1973 [2]] App]. No.: 400,753

cilitate the formation of a color original for use in a multi U.S. 355/4; 117/355; 282/28 R -color electrophotographic printing machine ar- [51] G03G 15/01 ranged to produce copies thereof. The sheet has an [58] Field of Search 355/4; 96/12; 1 17/355, opaque portion and a transparent portion correspond- I 17/8; 282/28 R ing to indicia thereon. Colored material is disposed on one surface of the sheet such that to an observer the [56] References Cited other surface is opaque with colored indicia being visi- UNITED STATES PATENTS ble through the transparent portion thereof.

101/336 X 4 Claims, 3 Drawing Figures Newman et Graham 73 57 99 H 02 ll 8 65 .9 07 7 23 US. Patent Sept. 30,1975 Sheet 1 of 2 U.S. Patent Sept. 30,1975 Sheet 2 of2 3,909,127

MULTI-COLOR ORIGINAL FOR AN ELECTROPHOTOGRAPHIC PRINTING SYSTEM BACKGROUND OF THE INVENTION This invention generally relates to a multi-color electrophotographic printing system, and more particularly concerns a laminated sheet arranged to facilitate the creation of a multi-color original adapted to be utilized in conjunction with the printing system.

In the process of electrophotographic printing, a photoconductive surface is charged to a substantially uniform potential in order to be sensitized. The charged photoconductive surface is, thereafter, exposed to a light image of an original document to be reproduced. In the areas of exposure, the charge is selectively dissipated in accordance with the light intensity reaching the photoconductive surface. Thus, an electrostatic latent image corresponding to the original document is recorded on the photoconductive surface. This electrostatic latent image recorded on the photoconductive surface is developed by bringing a developer mix into contact therewith. The typical developer mix is well known in the art and generally comprises a heat set'table thermoplastic powder known as toner particles. Toner particles are mixed with ferro-magnetic granules conventionally termed carrier granules which are selected so that the toner particles have the appropriate charge relative to the electrostatic latent image recorded on the photoconductive surface. Hence, when the developer mix is brought into contact with the charged photoconductive surface, the greater attractive force of the electrostatic latent image recorded thereon causes the toner particles to transfer from the carrier granules and adhere thereto. After the toner powder image is formed on the photoconductive surface, it is transferred therefrom to sheet of support material. In the case of multi-color electrophotographic printing, the foregoing process is repeated a plurality of cycles. Each cycle reproduces a discrete color of the original on the support material. After all of the single color toner powder images have been transferred to the support material, the multi-layered toner powder images have been transferred to the support material, the multi-layered toner powder image is permanently affixed thereto.

Heretofore, an original document being reproduced was merely disposed in the electrophotographic printing machine. With the advent of multi-color electrophotographic printing, the art of creating an original document became highly significant. Generally, tapes and lettering pens are utilized to produce the varied colors desired in the original document. However, this does not facilitate the creation of a typed multi-color document. One technique would utilize a multi-colored typewriter ribbon which could then be utilized to produce the varied colors desired on the original document. However, conventional typewriters generally only have a black ribbon and create a black original document. The foregoing black original document does not readily lend itself to a multi-color usage. To date, no satisfactory technique has been developed wherein multi-color typed documents may be created in a simple fashion for utilization on a color electrophotographic printing machine. Ideally, it would be highly desirable to be able to create a multi-color document and have it automatically disposed within the electrophotographic printing machine for thereby.

Accordingly, it is a primary object of the present invention to improve the technique heretofore utilized for the creation of multi-color originals adapted to be employed in a multi-color electrophotographic printing machine.

reproduction SUMMARY OF THE INVENTION BRIEF DESCRIPTION OF THE DRAWINGS Other objects and advantages of the present invention will become apparent upon reading the following detailed description and upon reference to the drawings in which:

FIG. 1 is a schematic perspective view of the multicolor electrophotographic printing machine of the present invention;

FIG. 2 is a perspective view of the laminated sheet employed in the FIG. 1 printing system; and

FIG. 3 is a perspective view of the laminated sheet after colored indicia have been formed thereon.

While the present invention will be described in connection with the preferred embodiment, it will be understood that it is not intended to limit the invention to that embodiment. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.

DETAILED DESCRIPTION OF THE INVENTION For a general understanding of the disclosed multicolor electrophotographic printing system continued reference is had to the drawings. In the drawings, like reference numerals have been used throughout to designate like elements. The multi-color electrophotographic printing system, depicted schematically in FIG. 1, illustrates the various components utilized therein for producing multi-color copies from an original created on the laminated sheet of the present invention. Although the laminated sheet of the present invention is particularly well adapted for use in the foregoing electrophotographic printing system, it should become evident from the following discussion that it is equally well suited for use in a wide variety of printing machine applications and is not necessarily limited in its use to the particular embodiment shown herein.

Turning now to FIG. 1, the multi-color electrophotographic printing system illustrated therein employs indicia applying means or typewriter 10. Typewriter l0 issimilar to a conventional typewriter except that it includes a release mechanism therein adapted to advance the sheet being typed on to conveyor 12. Thus, the laminated sheet 14 (FIG. 2) of the present invention is disposed within typewriter 10. The typewriter operator thereupon types, in the normal fashion, the letter that is desired to be reproduced in the printing system. After completion of the typing, laminated sheet 14 with the indicia thereon is released from typewriter and advanced by a suitable roll mechanism therein to conveyor l2. Conveyor 12 moves laminated sheet 14 with the indicia thereon to sheet separator 16. Sheet separator 16 removes the uppermost sheet 74 of laminated sheet 14 and interposes between the transparent sheet 76 and the receiver sheet 84 a sheet of colored material 82. A suitable sheet separator will comprise a pair of sheet grippers which raise the uppermost sheet of laminated sheet 14 and tear it along serrated portion 80 thereof. Thereafter, the transparent portion 76 of laminated sheet 14 and the receiver portion 84 are separated from one another to permit the insertion of the desired colored sheet material 82 therebetween. It should be noted that one or more colored sheets may be interposed between transparent sheet 76 and receiver sheet 84 so as to form a colored original having one or more colors thereon. The exact construction and arrangement of laminated sheet 14 will be described hereinafter in greater detail with reference to FIGS. 2 and 3.

After the colored sheet is interposed between transparent sheet 76 and receiver sheet 84 of laminated sheet 14, laminated sheet 14 is advanced on endless conveyor 18 to platen 20 of the multi-color electrophotographic printing machine. A switch disposed on platen 20 is automatically activated as laminated sheet 14 is disposed thereon so as to energize the printing machine. The suitable switch may be a lever arm adapted to be depressed connecting the power supply with the printing machine.

With continued reference to FIG. 1, the multi-color electrophotographic printing machine illustrated therein will now be described in greater detail to illustrate the apparatus and method employed for producing a color copy from a color original. The electrophotographic printing machine employs a drum 22 mounted rotatably within the machine frame (not shown). Drum 22 has entrained about the exterior surface thereof photoconductive surface 24. A suitable photoconductive material is disclosed in US. Pat. No. 3,655,377 issued to Sechak in 1972. Drum 22 is rotated inthe direction of arrow 26 by a drive motor (not shown) within the printing machine. In this manner, photoconductive surface 24 passes sequentially through a series of processing stations. Drum 22 rotates at a substantially constant angular velocity and includes a timing disc mounted in the region of one end of the shaft thereof for triggering the machine logic. Thus, the rotation of drum 22 is coordinated with the various processing stations to produce the proper sequence of events thereat.

First, drum 22 rotates photoconductive surface 12 through charging station A. A corona generating device, indicated generally at 28, is positioned at charging station A. Corona generating device 28 extends in a longitudinal direction transversely across photoconductive surface 24 and generates a spray of ions. The spray of ions from corona generating device 28 charges photoconductive surface 24 to a relatively high substantially uniform potential. Preferably, corona generating device 28 is of the type described in US. Pat. No. 2,778,946 issued to Mayo in 1957.

After photoconductive surface 24 is charged to a substantially uniform potential, drum 22 rotates to exposure station D. At exposure station D, a color filtered light image of laminated sheet 14 is projected onto charged photoconductive surface 24. Exposure station B includes thereat a moving lens system, generally designated by the reference numeral 30, and a filter mechanism, shown generally at 32. Laminated sheet 14 is advanced to transparent platen 20 and disposed thereon face down. A lamp assembly, indicated generally at 34, is disposed beneath transparent platen 20 and illuminates laminated sheet 14 disposed thereon. Lamp assembly 34, lens system 30 and filter mechanism 32 are moved in a timed relationship with drum 22 to scan successive incremental areas of laminated sheet 14 disposed upon platen 20. This creates a flowing light image of laminated sheet 14 which is projected onto photoconductive surface 24. The irradiated areas of photoconductive surface 24 are discharged to form an electrostatic latent image thereon corresponding to the indicia of laminated sheet 14.

Filter mechanism 32 is adapted to interpose selected color filters into the optical light path. The appropriate color filter attenuates the light rays passing through lens 30 to record an electrostatic latent image on photoconductive surface 24 corresponding to a preselected spectral region of the electromagnetic wave spectrum, hereinafter referred to as a single color electrostatic latent image. A suitable moving lens system is disclosed in US. Pat. No. 3,062,108 issued to Mayo in 1962.

Drum 22 next rotates the single color electrostatic latent image recorded on photoconductive surface 24 to development station C. At development station C, three individual developer units, generally indicated by the reference numerals 36, 38 and 40, respectively, are positioned adjacent drum 22. A suitable development station of the type illustrated in FIG. 1 is disclosed in co-pending application Ser. No. 255,259 filed in 1972. The individual developer units of the development system are all of the type referred to generally as magnetic brush developer units. A typical magnetic brush developer unit utilizes a magnetizable developer mix having carrier granules and toner particles therein. The developer mix is continually brought through a directional flux field to form a brush thereof. The electrostatic latent image recorded on photoconductive surface 24 is developed by bringing the brush of developer mix into contact therewith. Toner particles are attracted from the brush of developer mix to the electrostatic latent image recorded on photoconductive surface 24, thereby forming a powder image on photoconductive surface 24. Each of the respective developer units contain discretely colored toner particles corresponding to the complement of the spectral region of the wavelength of light transmitted through filter 32. By way of example, a green filtered electrostatic latent image is rendered visible by depositing green absorbing magenta toner particles on the electrostatic latent image recorded on photoconductive surface 24. Similarly, blue and red latent images are developed with yellow and cyan toner particles, respectively.

After the single color electrostatic latent image recorded on photoconductive surface 24 is developed with suitably colored toner particles, drum 22 rotates to transfer station D. At transfer station D, the toner powder image adhering to photoconductive surface 24 is transferred to a sheet of final support material 42. Final support material 42 may be, amongst others, plain paper or a sheet of thermoplastic material. The

transfer roll, shown generally at 44, is arranged to have support material 42 secured releasably thereto to recirculate therewith. Transfer roll 44 rotates, in the direction of arrow 46, at substantially the same angular velocity as drum 22. This permits successive single color toner powder images to be transferred from photoconductive surface 24 to support material 42. Transferroll 44 is biased electrically to a potential of sufficient magnitude and polarity to attract electrostatically the toner powder image from photoconductive surface 24 to support material 42. A suitably electrically biased transfer roll 44 is described in U.S. Pat. No. 3,612,677 issued to Langdon et al. in 1971.

Prior to proceeding with the description of the printing process, the support material feeding arrangement for the printing machine depicted in FIG. 1 will be briefly discussed. Support material 42 is advanced from a stack 48 thereof disposed on a tray 50. Feed roll 52 cooperates with retard roll 54 to advance and separate the uppermost sheet from stack 48 disposed on tray 50. The advancing uppermost sheet moves into chute 56 which directs it into the nip between register rolls 58. Register rolls 58 align the sheet and advance it to transfer roll 44. Gripper fingers 60 secure releasably support material 42 to transfer roll 44. After a plurality of toner powder images have been transferred to support material 44 (in this case three), gripper fingers 60 space support material 42 from transfer roll 44. This enables gripper bar 62 to be interposed therebetween separating support material 42 from transfer roll 44.

Continuing now with the printing process, after support material 42 is separated from transfer roll 44, it advances on endless belt conveyor 64 to fixing station E. At fixing station E, a fuser, indicated generally at 66, permanently affixes the multi-layered toner powder image to support material 42. One type of suitable fuser is described in U.S. Pat. No. 3,498,592 issued to Moser et al. in 1970.

After the fixing process, support material 42 is advanced by endless belt conveyors 68 and 70 to catch tray 72. Catch tray 72 is positioned to readily enable the machine operator to remove the completed color copy therefrom.

Invariably some residual toner particles remain on photoconductive surface 24 after the toner powder images have been transferred from the electrostatic latent image recorded thereon to support material 42. These residual toner particles are removed from photoconductive surface 24 as it passes through cleaning station E. Initially, the toner particles are brought under the influence of a cleaning corona generating device (not shown) arranged to neutralize the electrostatic charge remaining on the toner particles and photoconductive surface 24. The neutralized toner particles are then cleaned from photoconductive surface 24 by a rotatably mounted fibrous brush 72 in contact therewith. A suitable brush cleaning device is described in U.S. Pat. No. 3,590,412 issued to Gerbasi in 1971. As shown in FIG. 1, rotatably mounted brush 73 removes the residual toner particles remaining on photoconductive surface 24. Thus, photoconductive surface 24 has the residual toner particles cleaned therefrom prior to repeating the foregoing print cycle for the next successive toner powder image.

It is believed that the foregoing description is sufficient to illustrate the general operation of a multi-color electrophotographic printing system employing laminated sheet 14 therein asan original document.

Referring now to the specific structural configuration of laminated sheet 14, FIG. 2 depicts schematically, in perspective, laminated sheet 14 prior to being placed in typewriter 10 without the indicia or typewriter characters disposed thereon. As shown in FIG. 2, laminated sheet 14 includes a first sheet, shown generally at 74. First sheet 74 may be a suitable sheet of plain paper and is adapted to have the typewriter characters printed thereon by typewriter 10. It should be noted that typewriter 10 is a pressure type of apparatus where ink is deposited on first sheet 74 due to the pressure of the keys. Disposed beneath first sheet 74 is a substantially transparent sheet 76. First sheet 74 is secured to transparent sheet 76 in the marginal region 78 thereof. First sheet 74 includes a serrated portion 80 to facilitate the separation thereof from transparent sheet 76. Transparent sheet 76 includes a pressure transferrable coating 82 secured thereto. As the typewriter keys impact first sheet 74 inscribing the characters desired thereon, the pressure therefrom causes the pressure transferrable coating 82 to be transferred from transparent sheet 76 to receiver sheet 84 beneath the characters inscribed on first sheet 74. Receiver sheet 84 is secured in marginal region 78 to transparent sheet 76. Thus, after typewriter 10 has produced the desired information on first sheet 74, transparent sheet 76 will have an opaque portion and a transparent portion, the transparent portion corresponding to the letters of characters typed on first sheet 74 and the opaque portion corresponding to the remainder of the sheet. Preferably, the pressure transferrable material or coating 82 is white. Thus, when transparent sheet 76 is viewed, it will appear to be a white sheet with transparent letters inscribed thereon corresponding to the letters typed on first sheet 74 by typewriter 10. It should be noted that pressure transferrable material is now deposited beneath the characters inscribed on first sheet 74 onto receiver sheet 84.

By way of example, first sheet 74 is plain sheet of relatively light weight paper, transparent sheet 76 is a sheet of substantially transparent thermoplastic material. Pressure transferrable coating 82 preferably is white and adhers to transparent sheet 76. Finally, receiver sheet 84 is, preferably, a 24 pound bond paper. Coating 82 may comprise a quantity of extremely pulverent opaque material such as extremely finely powdered chalk and a suitable dilute vehicle to produce a lacquer of the desired consistency so as to form a pulverent pigment which is deposited on and adheres to transparent sheet 76. Coating 82 employs only enough lacquer or other suitable vehicle so as to adhere the minute grains of chalk one to the other and the whole film to the surface of transparent sheet 76. To this extent, opaque coating 82 may be said to have very little cohesion and adhesion and is separable when the appropriate pressure is applied thereto. It should be noted that a suitable film may be applied to pulverent pigment to insure that it adheres to transparent sheet 76 and separates therefrom only under the appropriate pressure.

Referring now to FIG. 3, there is shown a portion of laminated sheet 14 wherein first sheet 74' is separated therefrom and a color sheet 86 is inserted between transparent sheet 76 and receiver sheet 84. As shown in FIG. 1, sheet separator 16 removes first sheet 74 from transparent sheet 76 after typewriter 10 has inscribed the appropriate characters thereon. Thus, transparent sheet 76 is now opaque except in the regions of the inscribed characters wherein it is transparent. This enables a colored sheet 86 to be inserted between transparent sheet 76 and receiver sheet 84. The colored portions of the sheet will be visible only in the regions wherein sheet 76 is transparent. These regions will only be where typewriter 10 has inscribed the appropriate characters. For example, as shown in FIG. 3, typewriter 10 has inscribed the letters X-E-R-O-X on the first sheet 74. This results in the pressure transferrable-coating 82 transferring from transparent sheet 76 to receiver sheet 84 in the regions of those letters. Thereafter, sheet separator 16 inserts the appropriate col-. ored sheet 86 between transparent sheet 76 and receiver sheet 84. This produces a laminated sheet having a white appearance with the exception of the area wherein the letters have been inscribed thereon. In the region of the letters X-E-R-O-X the color from colored sheet 86 will be visible. Thus, the observer will see a white sheet having colored letters thereon. Preferably, colored sheet 86 is formed from colors spectrophotometrically compatible with photoconductive surface 24. By way of example, some suitable colors are cyan, magenta, yellow, blue, green, red and black.

While the invention has been described in connection with a first opaque sheet secured to a transparent sheet, one skilled in the art will appreciate that the invention is not necessarily so limited and that the first opaque sheet may not be required. For example, if the typewriter ribbon is removed, the indicia may be typed directly onto the transparent sheet, thereby eliminating the necessity for a first opaque sheet.

In recapitulation, it is evident that the system of the present invention takes a laminated sheet, types the desired information thereon and inserts the requisite colored material therebehind so as to produce an original document having one or more colors for reproduction in an electrophotographic printing machine. The original document is then copied by the electrophotographic printing machine producing one or more copies therefrom corresponding in color to the original.

Thus, it is apparent that there has been provided in accordance with the present invention an electrophotographic printing system that fully satisfies the objects, aims and advantages set forth above. While this invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications and variations as fall within the broad scope of the appended claims.

What is claimed is: I

l. A multi-color electrophotographic printing system, including:

an original comprising a substantially transparent sheet having a coating of pressure transferrable material adhering to one surface thereof, a receiver sheet secured to one marginal region of the transparent sheet, the receiver sheet being disposed adjacent to the surface of the transparent sheet having the transferrable material adhering thereto, a sheet of colored material interposed between the receiver sheet and the transparent sheet, the colored sheet being visible only in the regions where indicia applied to the transparent sheet transferred the pressure transferrable material from the transparent sheet to the receiver sheet, and a first sheet secured in the marginal region to the transparent sheet on the surface thereof opposed from the pressure transferrable material and arranged to receive the indicia thereon;

means for applying the desired indicia to the first sheet, thereby transferring the pressure transferrable material from the transparent sheet to the receiver sheet in the regions of the indicia;

means for automatically separating the first sheet of said original from the transparent sheet thereof; a photoconductive member; means for charging said photoconductive member to a substantially uniform level;

meand for exposing said original to create successive single color images which are projected onto said charged photoconductive member recording thereon successive single color electrostatic latent images;

means for developing the successive single color electrostatic latent images with toner particles complementary in color to the single color light images;

means for transferring successive toner powder images from the corresponding electrostatic latent image to a sheet of support material, each toner powder image being transferred in superimposed registration with the prior one; and

means for affixing permanently the multi-layered toner powder image to the sheet of support material creating a color copy conforming to said original.

2. A printing machine as recited in claim 1, further including means for automatically advancing said original from said indicia applying means to said separating means and then to said exposing means. 3. A printing system as recited in claim 2, wherein said first sheet includes a serrated portion in the mar ginal region thereof secured to said transparent sheet facilitating the separation of said first sheet from said transparent sheet.

4. A printing system as recited in claim 3, wherein the pressure transferrable material of the transparent sheet of said original is preferably white. 

1. A multi-color electrophotographic printing system, including: an original comprising a substantially transparent sheet having a coating of pressure transferrable material adhering to one surface thereof, a receiver sheet secured to one marginal region of the transparent sheet, the receiver sheet being disposed adjacent to the surface of the transparent sheet having the transferrable material adhering thereto, a sheet of colored material interposed between the receiver sheet and the transparent sheet, the colored sheet being visible only in the regions where indicia applied to the transparent sheet transferred the pressure transferrable material from the transparent sheet to the receiver sheet, and a first sheet secured in the marginal region to the transparent sheet on the surface thereof opposed from the pressure transferrable material and arranged to receive the indicia thereon; means for applying the desired indicia to the first sheet, thereby transferring the pressure transferrable material from the transparent sheet to the receiver sheet in the regions of the indicia; means for automatically separating the first sheet of said original from the transparent sheet thereof; a photoconductive member; means for charging said photoconductive member to a substantially uniform level; meand for exposing said original to create successive single color images which are projected onto said charged photoconductive member recording thereon successive single color electrostatic latent images; means for developing the successive single color electrostatic latent images with toner particles complementary in color to the single color light images; means for transferring successive toner powder images from the corresponding electrostatic latent image to a sheet of support material, each toner powder image being transferred in superimposed registration with the prior one; and means for affixing permanently the multi-layered toner powder image to the sheet of support material creating a color copy conforming to said original.
 2. A printing machine as recited in claim 1, further including means for automatically advancing said original from said indicia applying means to said separating means and then to said exposing means.
 3. A printing system as recited in claim 2, wherein said first sheet includes a serrated portion in the marginal region thereof secured to said transparent sheet facilitating the separation of said first sheet from said transparent sheet.
 4. A printing system as recited in claim 3, wherein the pressure transferrable material of the transparent sheet of said original is preferably white. 